Breast cancer survivors are at increased risk of arm lymphedema, and current clinical guidelines recommend that they avoid upper body exercise. In an investigation that enrolled women with a history of unilateral breast cancer, surgical removal of at least 2 lymph nodes, and no evidence of breast cancer–related lymphedema, Schmitz and colleagues randomly assigned the women to either a 1-year weight lifting intervention or a no-exercise control group and found that the progressive weight lifting program was not associated with an increased incidence of arm lymphedema.

Experimental evidence suggests that subpopulations of self-renewing leukemic stem cells (LSCs) are able to initiate and maintain the malignant cell population in acute myeloid leukemia. In a prospective study, Gentles and colleagues identified a gene expression profile that distinguished self-renewing LSC-enriched subpopulations of cells from other acute myeloid leukemia tumor cells. In an analysis of tumor samples and clinical data from 4 independent cohorts of patients with acute myeloid leukemia, the authors found that high LSC scores—reflecting the relative expression of the LSC-enriched genes—were independently associated with worse overall, event-free, and relapse-free survival.

To assess the effects of prenatal micronutrient supplementation on functional outcomes in children, Christian and colleagues examined intellectual and motor function in a cohort of 676 rural Nepalese children aged 7 to 9 years whose mothers had been randomly assigned to receive different combinations of prenatal micronutrient supplements. The authors report that general intellectual test performance and aspects of executive and motor function were better among children whose mothers had received prenatal iron, folic acid, and vitamin A supplementation compared with children of control group mothers who received vitamin A alone.

A majority of patients with Cowden syndrome—a rare autosomal dominant disorder characterized by high risks of breast, thyroid, and other cancers—and a small minority of patients with Cowden-like syndrome have germline mutations in the tumor suppressor PTEN gene. In a preliminary study, Bennett and colleagues Article found that among PTEN mutation–negative individuals with Cowden syndrome and Cowden syndrome–like features, hypermethylation and inactivation of a novel gene, KILLIN— which shares the same transcription start site as PTEN— were common and associated with higher risks of breast and renal cancer compared with PTEN mutation–positive individuals. In an editorial, Article Jelovac and Park discuss mechanisms of tumor suppressor gene inactivation in Cowden and Cowden-like syndromes.

A Behavioral and Systems View of Professionalism

Definitions of professionalism are often abstract and provide little description of what professional behaviors look like in practice. Lesser and colleagues propose a model of professionalism that encompasses specific and observable behavior competencies that can be taught and refined and describe ways in which professional behaviors are influenced by the environmental and organizational context of medical practice.

“I suspect what touches the children is that the animals are a concrete and engaging way to tell and show my interests and passions, and this openness helps establish trust.” From “The Day the Computer Tried to Eat My Alligator.”

Studies show a significant burden of traumatic brain injury in youthful motorcyclists and a much higher risk of brain injury for those riding in states without laws requiring riders of all ages to wear helmets.